MANILA: The body of 22-year-old pedicab driver Eric Sison lies in a coffin in a Manila slum with a chick pacing across his casket, placed there in keeping with a local tradition to symbolically peck at the conscience of his killers.

Cellphone video footage circulating on social media purports to capture the moment Sison was killed last month when, according to local officials, police were looking for drug pushers in the Pasay township of the Philippines' capital.

A voice on the video, recorded by a neighbour according to newspaper reports, can be heard shouting "Don't do it, I'll surrender!". Then there is the sound of gunfire.

A poster near the coffin, which lies beside a stinking canal cut between ramshackle homes, demands "Justice for Eric Quintinita Sison". A handpainted sign reads: "OVERKILL - JUSTICE 4 ERIC."

These are rare tokens of protest against a surge of killings unleashed since Rodrigo Duterte became president of the Philippines just over two months ago and pledged to wage war on drug dealers and crush widespread addiction to methamphetamine.

Very little stands in the way of his bloody juggernaut.

Last week the number of people killed since July 1 reached 2,400: about 900 died in police operations, and the rest are "deaths under investigation", a term human rights activists say is a euphemism for vigilante and extrajudicial killings.

Duterte's office did not immediately respond to a request for comment on this report.

OPPONENTS ASSAILED

Reuters interviews reveal that the police's Internal Affairs Service (IAS) and the Commission on Human Rights (CHR) are so overwhelmed by the killings that they can investigate only a fraction, and there is scant hope of establishing many as unlawful because witnesses are too terrified to come forward.

Meanwhile, the immense popularity of Duterte's crusade and a climate of fear whipped up by the bloodletting have together silenced dissent from civil society. Hardly anyone turned up at candlelight vigils in Manila recently to protest against extrajudicial killings.

Even as the death toll rose, a July poll by Pulse Asia put Duterte's approval rating at 91 percent.

Anxious reminders by the Catholic Church of the commandment 'thou shalt not kill' make few headlines in the predominantly Catholic country, with newspapers preferring to carry breathless accounts of the latest slayings.

Duterte has delivered withering attacks on his chief critic, Senator Leila de Lima, accusing her of dealing in drugs herself and having an affair with her driver.

"It's only the president who can stop this," de Lima told Reuters last week, deploring what she described as the "madness" that led in one case to a five-year-old girl being shot in the head.

"How many more of these cases of collateral damage are we willing to bear before we can really start screaming about it?" she asked.

As for critics abroad, Duterte pours scorn on them in language larded with curses.

He lambasted the United Nations after it criticised the surge in killings and he turned down a meeting with UN Secretary General Ban Ki-moon at a summit in Laos this week.

Duterte will meet Barack Obama in Laos on Tuesday, although he has made it clear in advance that he will take no lecture on human rights from the US president, when in the United States he alleged "black people are being shot even if they are already lying down".

"EVERYONE IS AFRAID"

Duterte may intensify the crackdown after 14 people were killed on Friday in a bomb attack at a market in his hometown, Davao. Police blamed the Abu Sayyaf, an Islamic State-linked group Duterte has vowed to destroy, but his war on the drug trade is making enemies elsewhere and the attack quickened rumours of a plot to kill him.

Duterte has declared a nationwide "state of lawlessness" after the blast that authorises troops to reinforce the police with checkpoints and patrols.

He has managed with remarkable speed to nationalise a vicious model for fighting crime that he pioneered as mayor of Davao for 22 years.

Rights groups documented hundreds of suspicious murders in Davao on Duterte's watch and say death squads operated with impunity there. "The Punisher", as some call him, denies ordering extrajudicial killings but he does not condemn them.

Across the country now, lists of suspected drug pushers are being provided to police by neighbourhood chiefs, adding to a sense of fear and distrust across communities.

Politicians of all hues have gone quiet, and a Senate enquiry led by de Lima only has the power to propose legislation, not stop the killers in their tracks.

INVESTIGATORS SWAMPED

Chief Superintendent Leo Angelo Leuterio, who heads the IAS, says it is his office's responsibility to investigate every discharge of firearms involving police. But with only about 170 investigators nationwide, the IAS is able to deal with just 30 percent of the roughly 30 cases coming in every day.

"Our resources are breaking at the seams," said Leuterio.

The IAS chief is supposed to be a civilian to ensure its independence but Leuterio is a policeman who spent 13 years of his career in Duterte's hometown, Davao. He says he is unbiased and has a track record of dismissing hundreds of officers for misconduct.

The CHR, for its part, is looking at just 259 of the 2,000-plus killings since July 1. Its forensics team of 14 is swamped and in their cramped office investigators probing possible extrajudicial killings are handling just 12 dossiers.

The commission says its biggest obstacle is that witnesses are hard to find.

One person who did come forward is Harrah Kazuo, whose husband and father-in-law were severely beaten and shot dead in a police station, according to a CHR report. She told Reuters that when the police entered their home without a warrant they even removed her toddler's underwear to search for drugs.

Police have not commented on what happened in the home, but two officers have been arrested and charged with murder in connection with the case. Kazuo has been taken into witness protection by the CHR.

She is a rare protesting voice in an environment where many are fearful.

On August 29, police told reporters they had opened fire that night on a drug suspect in Tondo, a dirt-poor and densely populated district of Manila.

A Reuters reporter looked into the suspect's one-room home and saw a mattress splattered with blood. He asked a neighbour how many shots had been fired, but the man replied: "Sorry, my friend. I didn't hear a single shot," and walked away.